Question

100 POINTS PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Rachel found that the time it takes for her to make her favorite desert decreases the more times she makes its. The time is takes in minutes(M) can be modeled by: M=72-0.75n, where n is the number of times that rachel has made the desert.
A. how long will it take rachel to make her desert the fifth time?

B. after how many times will rachel be able to make her desert in 63 minutes?

C. How long will it take rachel to make her desert the 40th time? Do you think this is reasonable?

Answer 1

A: 68.25 minutes

B: 12 times

C: 42 mins and you decide this part I actually don't know. But I think it could be reasonable, after 40 times someone should get pretty good at it.

Explanation:

a: 72 -0.75*5 = 68.25

b: M=63=72-0.75n

subtract 72 from each side: -9 = -0.75n

divide each side by -0.75: n = 12

so 12 times

c: 72 - 0.75(40) = 42 minutes. Now this could be is reasonable, but we don't know what their desert is. But 40 times is a lot of practice.